lpcware

LPC43xx Max External Flash/SDRAM?

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by RandyM on Tue Apr 30 11:20:56 MST 2013

I'm interested in using the EMC controller for flash and SDRAM, though I'm confused on what the limits are.  What is the maximum memory addressable by the EMC?  When reading the <a href="http://www.nxp.com/documents/user_manual/UM10503.pdf">user manual</a>, I'm having a hard time connecting the dots.  Here's what is throwing me for a loop:


 


<table border="0">
<tbody>
<tr>
<td style="border: 1px solid #000000;"><strong>Memory</strong></td>
<td style="border: 1px solid #000000;"><strong>Chapter 3, Memory Mapping, fig 4</strong></td>
<td style="border: 1px solid #000000;"><strong>Chapter 21, EMC, section 21.3</strong></td>
</tr>
<tr>
<td style="border: 1px solid #000000;">Flash</td>
<td style="border: 1px solid #000000;">16MB for each CS, 64MB total</td>
<td style="border: 1px solid #000000;">Refers to to 512MB, 256MB, and 128MB parts, which all exceed the per CS and total MB stated in the mapping</td>
</tr>
<tr>
<td style="border: 1px solid #000000;">SDRAM</td>
<td style="border: 1px solid #000000;">128MB for DCYS0, 258MB for the other 3, 896MB total</td>
<td style="border: 1px solid #000000;">"... upt to 256MB of data,' far less that 896MB!</td>
</tr>
</tbody>
</table>

 


Am I misinterpretting the tables and text?  Does the text mix mega-bits (Mb) and mega-bytes (MB) with a singular acronym (MB)?  896MB of SDRAM seems very disproportionate to 64MB of flash.


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